Investment Objectives and Goals |
Apr. 30, 2026 |
|---|---|
| MFS Core Bond Fund | |
| Prospectus [Line Items] | |
| Risk/Return [Heading] | MFS® Core Bond Fund Summary of Key Information |
| Objective [Heading] | Investment Objective |
| Objective, Primary [Text Block] | The fund’s investment objective is to seek total return with an emphasis on current income, but also considering capital appreciation. |
| MFS Lifetime Income Fund | |
| Prospectus [Line Items] | |
| Risk/Return [Heading] | MFS® Lifetime® Income Fund Summary of Key Information |
| Objective [Heading] | Investment Objective |
| Objective, Primary [Text Block] | The fund’s investment objective is to seek total return through a combination of current income and capital appreciation. |
| MFS Lifetime 2030 Fund | |
| Prospectus [Line Items] | |
| Risk/Return [Heading] | MFS® Lifetime® 2030 Fund Summary of Key Information |
| Objective [Heading] | Investment Objective |
| Objective, Primary [Text Block] | The fund’s investment objective is to seek a high level of total return consistent with its asset allocation until the approximate retirement year in the fund's name; thereafter, the fund will seek total return through a combination of current income and capital appreciation. The asset allocation of the fund will change over time. |
| MFS Lifetime 2035 Fund | |
| Prospectus [Line Items] | |
| Risk/Return [Heading] | MFS® Lifetime® 2035 Fund Summary of Key Information |
| Objective [Heading] | Investment Objective |
| Objective, Primary [Text Block] | The fund’s investment objective is to seek a high level of total return consistent with its asset allocation until the approximate retirement year in the fund's name; thereafter, the fund will seek total return through a combination of current income and capital appreciation. The asset allocation of the fund will change over time. |
| MFS Lifetime 2040 Fund | |
| Prospectus [Line Items] | |
| Risk/Return [Heading] | MFS® Lifetime® 2040 Fund Summary of Key Information |
| Objective [Heading] | Investment Objective |
| Objective, Primary [Text Block] | The fund’s investment objective is to seek a high level of total return consistent with its asset allocation until the approximate retirement year in the fund's name; thereafter, the fund will seek total return through a combination of current income and capital appreciation. The asset allocation of the fund will change over time. |
| MFS Lifetime 2045 Fund | |
| Prospectus [Line Items] | |
| Risk/Return [Heading] | MFS® Lifetime® 2045 Fund Summary of Key Information |
| Objective [Heading] | Investment Objective |
| Objective, Primary [Text Block] | The fund’s investment objective is to seek a high level of total return consistent with its asset allocation until the approximate retirement year in the fund's name; thereafter, the fund will seek total return through a combination of current income and capital appreciation. The asset allocation of the fund will change over time. |
| MFS Lifetime 2050 Fund | |
| Prospectus [Line Items] | |
| Risk/Return [Heading] | MFS® Lifetime® 2050 Fund Summary of Key Information |
| Objective [Heading] | Investment Objective |
| Objective, Primary [Text Block] | The fund’s investment objective is to seek a high level of total return consistent with its asset allocation until the approximate retirement year in the fund's name; thereafter, the fund will seek total return through a combination of current income and capital appreciation. The asset allocation of the fund will change over time. |
| MFS Lifetime 2055 Fund | |
| Prospectus [Line Items] | |
| Risk/Return [Heading] | MFS® Lifetime® 2055 Fund Summary of Key Information |
| Objective [Heading] | Investment Objective |
| Objective, Primary [Text Block] | The fund’s investment objective is to seek a high level of total return consistent with its asset allocation until the approximate retirement year in the fund's name; thereafter, the fund will seek total return through a combination of current income and capital appreciation. The asset allocation of the fund will change over time. |
| MFS Lifetime 2060 Fund | |
| Prospectus [Line Items] | |
| Risk/Return [Heading] | MFS® Lifetime® 2060 Fund Summary of Key Information |
| Objective [Heading] | Investment Objective |
| Objective, Primary [Text Block] | The fund’s investment objective is to seek a high level of total return consistent with its asset allocation until the approximate retirement year in the fund's name; thereafter, the fund will seek total return through a combination of current income and capital appreciation. The asset allocation of the fund will change over time. |
| MFS Lifetime 2065 Fund | |
| Prospectus [Line Items] | |
| Risk/Return [Heading] | MFS® Lifetime® 2065 Fund Summary of Key Information |
| Objective [Heading] | Investment Objective |
| Objective, Primary [Text Block] | The fund’s investment objective is to seek a high level of total return consistent with its asset allocation until the approximate retirement year in the fund's name; thereafter, the fund will seek total return through a combination of current income and capital appreciation. The asset allocation of the fund will change over time. |